Re: NORTHERN PACIFIC BOXCAR TRUCKS


Jack Mullen
 

Gene Green wrote:

Thank Richard (and Dave, who contacted me off list),
I should have been more clear in my original post. (I knew what I was thinking and figured you guys would all know, too. We're all clairvoyant, right?)

Using ASF A-3s and Barber S-2s as examples, would it be true that the only bolster that would fit the sideframe would have to come from the same manufacturer?
Gene,
I'm not a mechanical guy, but from what I've learned on the job and in derailment cause-finding training, it's true that each of the major "stabilized" truck designs (the above plus National C-1) has a different, proprietary arrangement of wedges that requires a match between bolster and sideframe. That said, both ASF and Barber designs were licensed to other truck manufacturers, eg. Scullin or Symington. The licensed products may well have been interchangeable with the "parent" design. But I suspect that the advent of "Ride Control" or "Stabilized" trucks pretty much ended the practice of ordering truck sideframes and bolsters piecemeal.

From a modeling viewpoint, in looking at the various mfrs pages in the Cycs, I have not noticed significant differences in the appearance of the bolster end that would distinguish, say a Symington Ride Control truck bolster from an ASF one. You and others have probably paid more attention to this, however.

Jack Mullen

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